Current email systems typically include whitelists of trusted email addresses and domains. An incoming email from a whitelisted entry is presumed to be legitimate, and is therefore delivered to the addressee without being subject to scanning for spam or other processing to check for malicious email. Checking for spam and other security processing consumes both time and computing resources, so it is desirable to be able to bypass it when email is known to be legitimate.
Currently available automated whitelisting techniques use very simple mechanisms, such as adding all parties to whom a user sends email to a whitelist. Whitelists created this way often include entries that are not truly legitimate. For example, a user might send an email to a business from whom the user does not wish to receive automatically generated commercial emails. The user might even send an email requesting to be removed from an email list. Clearly, in situations such as these, the user does not want the recipient added to the whitelist. These currently available simple whitelisting mechanisms also lead to the creation of very large whitelists that are typically very difficult and time consuming for users to manage. This problem becomes much worse when these simple mechanisms are applied for multiple users at a gateway or domain level.
The Automatic Whitelisting Application describes methodologies that a local client or gateway can use to better manage whitelists, by using time and threshold based values to automatically promote provisional whitelist entries to permanent status. The Automatic Whitelisting Application also discusses using a threshold to promote an entire domain to permanent status, such that an email from anyone at a whitelisted domain is accepted as non-spam.
The invention of the Automatic Whitelisting Application is very useful, but lacks a mechanism for establishing associative trust that could allow quicker provisional promotion for “friend of friend” senders. What is needed are methods, computer readable media and computer systems for automatically sharing whitelist data between users or domains while at the same time maintaining privacy at a user/domain level.